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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 20 |
| 3 | 80 |
| 4 | 320 |
| 5 | 1280 |
| 6 | 5120 |
| 7 | 20480 |
| 8 | 81910 |
| 9 | 327600 |
| 10 | 1310250 |
| 11 | 5240400 |
| 12 | 20959200 |
| 13 | 83827200 |
| 14 | 335270400 |
| 15 | 1340928000 |
| 16 | 5363097690 |
| 17 | 21449933820 |
| 18 | 85789908630 |
| 19 | 343120332420 |
| 20 | 1372324139280 |
| 21 | 5488667867520 |
| 22 | 21952156999680 |
| 23 | 87798571269120 |
[1,5,20,80,320,1280,5120,20480,81910,327600, 1310250,5240400,20959200,83827200,335270400, 1340928000,5363097690,21449933820,85789908630, 343120332420,1372324139280,5488667867520, 21952156999680,87798571269120] |